{"product_id":"fits-gm-ls-engines-with-1-4in-wide-flange","title":"Fits GM LS Engines with 1\/4in Wide Flange","description":"Each PROFORM 12.9 Steel (equiv. Grade 8+) Header Bolt is permanently assembled with a pair of special washers. When the bolt is torqued to 28+ ft-lbs, the washers super-hardened external teeth bite into and grip the bottom of the bolt head and the top surface of the header. After being self-locked in this manner, any bolt-loosening rotation is blocked by a wedge-locking action created by the washers interfacing, matching cams. It's an uphill climb: vibration that might ordinarily loosen the bolt actually increases the wedge-locking tension, securing the bolt even more. Because this simple wedge-locking method uses tension instead of friction, contact with oil actually facilitates the wedge effect. When changing headers, PROFORM Header Bolts can be untightened with a normal wrench, lubricated, and reused.","brand":"Proform","offers":[{"title":"Default Title","offer_id":52963702866214,"sku":"BCHW_66754","price":34.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0672\/5697\/5654\/files\/acd45581ee653.jpg?v=1775237026","url":"https:\/\/ossparts.com\/products\/fits-gm-ls-engines-with-1-4in-wide-flange","provider":"Operational Speed Supply","version":"1.0","type":"link"}